Accuracy of EBRA‐cup measurements after reconstruction of severe acetabular defects at revision THR

Renkawitz²,

et al. 2020

Purpose Polyethylene (PE) wear remains a common reason for revision surgery following total hip arthroplasty (THA). An established treatment method is isolated liner exchange in a well-fixed acetabular cup and entails a known high risk of hip dislocation after revision surgery. The purpose of this retrospective study was to determine the rate of hip dislocation after liner exchange. Methods Patients were included if (1) the PE liner was removable, (2) the acetabular shell was stable with acceptable orientation, (3) no osteolysis around the acetabular cup was found and (4) no dislocation of the THA occurred before revision surgery. We reviewed medical histories and performed radiological measurements using Einzel-Bild-Röntgen-Analyse (EBRA) software. EBRA measurements and statistical investigations were performed by two independent investigators. Results A total of 82 patients were included in our study. Mean follow-up was six (range: 3.6–9.9) years. In 13 (15.8%) patients THA dislocations occurred at a mean postoperative period of 20.2 (range: 1–44) weeks after revising the PE liner. This is equivalent to an absolute risk increase of 16% after revision surgery, which results in a number needed to harm of 6. This means that every sixth patient with isolated liner exchange can expect to experience dislocation due to wear. Conclusion In conclusion, isolated exchange of the polyethylene liner because of wear showed a high risk of dislocation and further cup revision. Our results suggest that the threshold for revising well-fixed components in the case of liner wear should be lowered. Trial Registration number and date of registration Number: 20140710-1012 and Date: 2016-03-09.

Section: Discussionsupporting

confidence: 69%

Section: Discussionmentioning

confidence: 99%

High risk of hip dislocation following polyethylene liner exchange in total hip arthroplasty—is cup revision necessary?

Renkawitz²,

et al. 2020

“…For this purpose, EBRA is a suitable method for identifying and measuring the migration behavior of THA components [9,17,18]. While roentgen stereometric analysis (RSA) is considered the gold standard for migration measurements, Abrahams et al [10] recently reported good agreement between EBRA cup and RSA measurements of migration of acetabular cups in THA. Knowing that and applying a retrospective study design, we used EBRA cup software for our investigations of migration behavior.…”

Section: Discussionmentioning

confidence: 99%

“…ball markers) [9]. EBRA has a proven accuracy and sensitivity in detecting migration of more than 1 mm as compared to RSA (roentgen stereophotogrammetric analysis) [10,11].…”

Section: Introductionmentioning

confidence: 99%

Good mid-term results with the trident peripheral self-locking cup: a clinical evaluation and migration measurement with EBRA

Blum

et al. 2020

Introduction The most common cause of failure in total hip arthroplasty (THA) is aseptic loosening. Uncemented cup migration analysis by means of Einzel–Bild–Roentgen–Analyse (EBRA) has shown to be a good predictive indicator for early implant failure if the cup migrates more than 2 mm within 4 years after surgery. In this study, we performed a migration analysis of an uncemented peripheral self-locking (PSL) press-fit cup after 4 years follow-up. Materials and methods We retrospectively reviewed all patients who received a trident PSL press-fit cup at our department between 2004 and 2017. A total of 636 patients were identified. As inclusion criteria for radiological analysis, a minimum follow-up of 2 years was defined. We reviewed medical histories and performed radiological analysis using EBRA software. EBRA measurements and statistical investigations were performed by two independent investigators. Results A total of 149 cups in 146 patients (female 82; male 64) met our inclusion criteria. Mean age at surgery was 65 years (33–89). We found a significant improvement in the WOMAC score pre- to postoperative (p < 0.0001). EBRA migration analysis showed a mean total migration of 0.6 mm (0.0–8.2) over our follow-up period of 4 years. Of the investigated cups, 69.8% showed a migration rate smaller than 2 mm in the investigated follow-up. Conclusion The acetabular cup used in our study provides low migration at final follow-up. Therefore, a good long-term outcome can be expected for the PSL cup. Trial registration Trial registration number is 20181024-1875 and date of registration is 2018-10-24.

“…As tantalum balls must be implanted, this type of migration analysis involves a major effort and cannot be performed retrospectively [30,32,33]. Abraham showed that EBRA can accurately measure migration of uncemented acetabular components used at revision THA [34] and that EBRA cup and RSA measurements had a good agreement on the classification of components above and below 1 mm at 2 years with a sensitivity and specificity of 100% and 87%, respectively [34]. In cases of pelvic discontinuity and the use of augments and cages, the accuracy of EBRA migration measurements was significantly poorer [34].…”

Section: Discussionmentioning

confidence: 99%

Outcome and EBRA migration analysis of a reconstruction cage in acetabular revision arthroplasty: a clinical and radiological study

Blum

et al. 2020

Purpose Restoration cages and bone allografts have been proposed to manage severe acetabular bone defects. We aimed to investigate the migration behaviour of a restoration cup and impacted allograft bone in severe acetabular defects with Einzel-Bild-Röntgen-Analyse (EBRA). Methods Applying a retrospective study design, 64 cases treated between 2009 and 2016 were reviewed. We determined the preoperative Charlson Comorbidity Index (CCI), pre- to postoperative WOMAC score, blood loss and functional outcome. From preoperative x rays, the acetabular deficiencies were classified according to Paprosky. Cup migration analyses were performed with EBRA. Results Mean age at surgery was 73 (range: 38–93) years. According to the classification by Paprosky et al., 50% (n = 32) of our patients showed a type III B and 28.1% (n = 18) a type III A defect. Radiological follow-up for migration analysis was 35 (range: 4–95) months. Migration analysis showed a mean cup migration of 0.7 mm (range: 5.7–9.6) medial and 1.8 mm (range: 1.7–12.6) cranial. Conclusion In conclusion, acetabular restoration cages in combination with bone impaction grafting showed a low revision rate at a mean follow-up of 35 months. Mean cup migration revealed low rates after 2 years and suggested a stable postoperative implant position.